作者:Matthew K. Kiesewetter、Matthew N. Gard、Richard C. Reiter、Cheryl D. Stevenson
DOI:10.1021/ja062846u
日期:2006.12.1
The low temperature complete dehydrohalogenation of pentabromocyclododecene (C12H17Br5) with potassium tert-butoxide in THF followed by exposure to potassium metal leads to the formation of the anion radical of 1,5-di-trans-[12]annulene, which loses hydrogen and undergoes ring closure to form the anion radical of 11,12-dihydro-[8]annuleno-[6]annulene. This product can, in turn, be isolated as its neutral
五溴环十二碳烯 (C12H17Br5) 与叔丁醇钾在 THF 中的低温完全脱卤化氢,然后暴露于金属钾,导致形成 1,5-二-反式-[12] 环烯的阴离子自由基,其失去氢并经历闭环形成11,12-二氢-[8]环烯-[6]环烯的阴离子自由基。反过来,该产物可以通过用碘再氧化而作为其中性分子分离。在 18-crown-6 和叔丁醇钾的存在下,通过 1,5-己二炔的二聚反应获得的 [12] 环闭合,伴随着氢的损失,产生庚烯阴离子自由基。因此庚烯阴离子自由基前体是[12]环烯的1,7-二反式异构体。